[PD] Using Compare with pix_video

IOhannes m zmoelnig zmoelnig at iem.at
Wed May 26 16:28:36 CEST 2004

Ivan Franco wrote:
> yes, i know that non-power of 2 should be possible in gem right now. But 
> the error remains. Please take a look at the patch:

ok. i have had a look
and i still don't understand your error

1. do both images have the same dimensions ?
1a. really ? (you can check with [pix_info])

2. do both images have the same colorspace ?
   you are using [pix_grey] which converts the video-stream into 
grey-scale images (as opposed to RGBA); the still-image has to be 
greyscale too.
might give an error like:
   error: processDualImage [pix_compare]: no method to combine (Gray) and

probably use [pix_grey] for the image too.

3. if you get a warning "image is not a power-of-2" when loading, you 
can safely ignore it

4. the only other thing i noticed in the patch is, that you are 
converting to greyscale *after* some processing;
if you do it directly after capturing you would save memory and CPU

note: i have only tested this with [pix_film] (and the homer.avi) 
instead of [pix_video]; of course i had to change the dimensions of the 
dancer.JPG to 160x120 (this is the dimension of homer.avi) outside 
(using Gimp)


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